Typically, dollies are made of relatively heavy, solid wood rectangles or wood slats with a caster fastened on the underside of each corner. In order to protect items transported on these dollies it is often customary to provide raised ends that are covered with a protection device. Often the protection device is a rubber cap or carpeting. Usually, the carpeting or rubber caps are fastened to the wooden dollies using ordinary staples. However, since the wood used for dollies is usually of the hardwood variety, staples tend to fail to properly penetrate the wood. This causes the protective devices to loosen and exposes sharp staple ends that are hazardous to a user.
Recently, plastic dollies have been used. Plastic is preferable to wood for use a dolly material. Plastic is easier to clean and is less dense than wood. Therefore plastic dollies are lightweight and can be strengthened to be sufficiently sturdy. Plastic dollies are also often cheaper than wooden dollies and easier to manufacture. Plastic dollies also need to be covered to protect items being transported. However, dollies made of plastic suffer similar disadvantages as wooden dollies in that it is very difficult to penetrate the plastic material with staples to secure protective coverings; other securing mechanisms must be used to protect the items being moved.
Furthermore, it is highly advantageous and desirable to construct dollies so that they are easily disassembled for repair or replacement of various components of the dolly. This applies to both wooden and plastic dollies. In order to facilitate disassembly of the dolly the protective devices should also be readily removable. Plastic dollies that are easy to assemble and disassemble are also easier and cheaper to manufacture.